BD diesel 2WD Low on an Aisin

Has anyone installed this product from BD diesel on the Aisin tranny? The reverse in my truck with the 342 rear end seems kinda fast. The ability to have 2WD low has always attracted me - but I am coming from driving manual transmission trucks for 30 years and always wanted to be able to go really slow when backing up trailer in tight spots. But with an auto the constant clutch slipping is not a concern?